Zarr told me that exhorting patients to “get more exercise” was too vague. Last year, he decided to start trying something different. He stopped asking his patients, “Do you move?” and began asking “Where do you move?” He discovered that many spent very little time outdoors, and he began prescribing time outside for conditions as wide-ranging as ADHD, high blood pressure, asthma, obesity, anxiety, diabetes, and depression….

Why don’t more doctors prescribe nature? They used to do so regularly. The practice gained popularity in the mid-19th century as cities rapidly expanded… [and] concerns increased about overstimulation, noise, and smoke in cities. Doctors began prescribing their patients visits to more hospitable climes such as the Swiss Alps or the Adirondacks for afflictions from tuberculosis to mental health issues. A thriving industry of sanitariums sprang up with names like the Pines, Lake View, and River View.

This went into decline in the 20th century, but in the last couple decades we’ve started building a body of literature on the restorative effects of nature that explains why time outdoors is therapeutic.

I saw this at first hand this past week, when my wife was in the hospital (she’s fine, thanks). The El Camino Hospital in Mountain View’s new wing has patient rooms that all, without fail, look out on some natural scene— either looking outside at the hills, or at an interior courtyard full of bamboo and other plants. It’s quite striking how seriously they take the idea that exposure to nature speeds hospital recovery time.